diff --git a/thread.c b/thread.c
index 8b7f6364f7..ce93b1d46a 100644
--- a/thread.c
+++ b/thread.c
@@ -932,7 +932,7 @@ rb_thread_blocking_region(
     rb_thread_t *th = GET_THREAD();
 
     if (ubf == RUBY_UBF_IO || ubf == RUBY_UBF_PROCESS) {
-	ubf = ubf_select;n
+	ubf = ubf_select;
 	data2 = th;
     }